Recent research on children's inferencing has found that although adults typically adopt the pragmatic interpretation of some (implying not all), 5- to 9-year-olds often prefer the semantic interpretation of the quantifier (meaning possibly all). Do these failures reflect a breakdown of pragmatic competence or the metalinguistic demands of prior tasks? In 3 experiments, the authors used the visual-world eye-tracking paradigm to elicit an implicit measure of adults' and children's abilities to generate scalar implicatures. Although adults' eye-movements indicated that adults had interpreted some with the pragmatic inference, children's looks suggested that children persistently interpreted some as compatible with all (Experiment 1). Nevertheless, both adults and children were able to quickly reject competitors that were inconsistent with the semantics of some; this confirmed the sensitivity of the paradigm (Experiment 2). Finally, adults, but not children, successfully distinguished between situations that violated the scalar implicature and those that did not (Experiment 3). These data demonstrate that children interpret quantifiers on the basis of their semantic content and fail to generate scalar implicatures during online language comprehension.